KR101472187B1 - Optical element - Google Patents

Abstract

The present application relates to an optical element. The exemplary optical element may be a light dividing element, for example, an element that divides incident light into two or more kinds of light having different polarization states from each other. The optical element can be used, for example, for realizing a stereoscopic image.

Description

[0001] OPTICAL ELEMENT [0002]

This application relates to an optical element and its use.

Techniques for dividing light into two or more kinds of lights having different polarization states from each other can be usefully used in various fields.

The above-described optical segmentation technique can be applied, for example, to the production of stereoscopic images. The stereoscopic image can be implemented using binocular parallax. For example, when two two-dimensional images are input to the left and right eyes of a human, input information is transmitted and fused to the brain, so that a human senses a three-dimensional perspective and real feeling. In this process, .

The stereoscopic image generation technique can be usefully used in 3D measurement, 3D TV, camera, or computer graphics.

Japanese Patent Laid-Open No. 2005-049865 Korean Patent No. 0967899 Korea Patent Publication No. 2010-0089782

The present application provides an optical element and its use.

The present application is directed to optical elements. The term " optical element " may refer to any kind of optical device, optical component, or optical device that exhibits one or more intended functions. For example, the optical element may have the form of a sheet or a film. The optical element may be, for example, an element capable of dividing incident light into two or more kinds of lights having different polarization states from each other.

The optical element may include a liquid crystal layer. The liquid crystal layer included in the optical element may satisfy the condition of the following general formula (1).

[Formula 1]

X < 8%

X is a percentage of the absolute value of the amount of change in the retardation value of the liquid crystal layer after leaving the liquid crystal layer at 80 DEG C for 100 hours or 250 hours with respect to the initial retardation value of the liquid crystal layer.

The above X may be calculated, for example, as &quot; 100 x (| R ₀ - R ₁ |) / R ₀ . R ₀ is an initial retardation value of the liquid crystal layer, and R ₁ is a retardation value of the liquid crystal layer after the liquid crystal layer is left at 80 ° C for 100 hours or 250 hours. The X may be, for example, 7% or less, 6% or less, or 5% or less. The amount of change in the retardation value can be measured by the method shown in the following examples.

In one example, the difference between the refractive index in the in-plane slow axis direction and the refractive index in the in-plane fast axis direction may be in the range of 0.05 to 0.2, 0.07 to 0.2, 0.09 to 0.2, or 0.1 to 0.2 in the liquid crystal layer. The refractive index in the in-plane slow axis direction means the refractive index in the direction showing the highest refractive index in the plane of the liquid crystal layer and the refractive index in the fast axis direction can mean the refractive index in the direction showing the lowest refractive index on the plane of the liquid crystal layer . In general, in the optically anisotropic liquid crystal layer, the fast axis and the slow axis are formed in directions perpendicular to each other. Each of the refractive indices may be a refractive index measured with respect to light having a wavelength of 550 nm or 589 nm. The refractive index difference can be measured according to the manufacturer's manual using, for example, Axoscan of Axomatrix.

The liquid crystal layer may also have a thickness of about 0.5 占 퐉 to 2.0 占 퐉 or about 0.5 占 퐉 to 1.5 占 퐉.

The liquid crystal layer having the relationship of the refractive index and the thickness can realize the phase delay characteristic suitable for the application to which it is applied. In one example, the liquid crystal layer having the relationship of the refractive index and the thickness may be suitable for the optical element for light division.

The liquid crystal layer may include a polymerizable liquid crystal compound. For example, the liquid crystal layer may contain a polymerizable liquid crystal compound in a polymerized form. The term &quot; polymerizable liquid crystal compound &quot; may mean a compound containing a moiety capable of exhibiting liquid crystallinity, such as a mesogen skeleton, and further containing at least one polymerizable functional group. The phrase "the polymerizable liquid crystal compound is contained in a polymerized form" may mean a state in which the liquid crystal compound is polymerized to form the skeleton of the liquid crystal polymer in the liquid crystal layer.

The liquid crystal layer may further contain a polymerizable liquid crystal compound in a non-polymerized state, or may further contain a known additive such as a polymerizable non-liquid crystal compound, a stabilizer, a non-polymerizable non-liquid crystal compound, or an initiator.

In one example, the polymerizable liquid crystal compound contained in the liquid crystal layer may include a polyfunctional polymerizable liquid crystal compound and a monofunctional polymerizable liquid crystal compound.

The term "multifunctional polymerizable liquid crystal compound" may mean a compound containing two or more polymerizable functional groups in the liquid crystal compound. In one example, the polyfunctional polymerizable liquid crystal compound has from 2 to 10, from 2 to 8, from 2 to 6, from 2 to 5, from 2 to 4, from 2 to 3 Or two. Further, the term "monofunctional polymerizable liquid crystal compound" may mean a compound containing one polymerizable functional group in the liquid crystal compound.

The use of the multifunctional and monofunctional polymerizable compound together can effectively control the phase delay characteristics of the liquid crystal layer and can also stably maintain the implemented phase delay characteristics such as the optical axis of the phase delay layer or the phase delay value . The term &quot; optical axis &quot; may mean a slow axis or a fast axis when light passes through the area.

The liquid crystal layer is formed by mixing the monofunctional polymerizable liquid crystal compound in an amount of 0 to 100 parts by weight, 1 to 90 parts by weight, 1 to 80 parts by weight, 1 part by weight To 70 parts by weight, 1 part by weight to 60 parts by weight, 1 part by weight to 50 parts by weight, 1 part by weight to 30 parts by weight or 1 part by weight to 20 parts by weight.

Within this range, the mixing effect of the polyfunctional and monofunctional polymerizable liquid crystal compound can be maximized, and the liquid crystal layer can exhibit excellent adhesion with the adhesive layer. Unless specifically stated otherwise herein, the unit "parts by weight" may mean the ratio of weight.

In one example, the polyfunctional or monofunctional polymerizable liquid crystal compound may be a compound represented by the following formula (1).

[Chemical Formula 1]

Wherein A is a single bond, -COO- or -OCO-, and R ₁ to R ₁₀ are each independently selected from the group consisting of hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, or a substituent of the formula 2, R ₁ to R ₅ pair of two adjacent substituents of R ₆ to R ₁₀ or a pair of two substituents adjoining are connected to each other but form a benzene substituted with -OQP, R ₁ to at least one of R ₁₀ may be a substituent of the formula -OQP or 2, R ₁ to R _5, or two substituents R ₆ to R _10, at least one pair of the two adjacent substituents of the adjoining are connected to each other -OQP Wherein Q represents an alkylene group or an alkylidene group, and P represents an alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, or methacryloyl group Is a polymerizable functional group such as a silane group.

(2)

And R ₁₁ to R ₁₅ are each independently hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group or -OQP, The pair of adjacent two substituents R ₁₁ to R ₁₅ are connected to each other to form benzene substituted with -OQP, wherein at least one of R ₁₁ to R ₁₅ is -OQP, or two adjacent R ₁₁ to R ₁₅ P is an alkylene group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, or a methacryloyl group. A diacrylate group, a acryloyloxy group or a methacryloyloxy group.

The fact that two adjacent substituents in the formulas (1) and (2) are connected to each other to form benzene substituted with -OQP means that two adjacent substituents are connected to each other to form a naphthalene skeleton substituted with -OQP as a whole .

In the formula (2), "-" on the left side of B may mean that B is directly connected to benzene of the formula (1).

In the formulas (1) and (2), the term &quot; single bond &quot; means a case where no separate atom is present in a portion represented by A or B; For example, when A is a single bond in formula (I), benzene on both sides of A may be directly connected to form a biphenyl structure.

Examples of the halogen in the formulas (1) and (2) include, for example, chlorine, bromine, iodine and the like.

The term "alkyl group" means, for example, a straight chain or branched chain alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms unless otherwise specified Or a cycloalkyl group having 3 to 20 carbon atoms, 3 to 16 carbon atoms, or 4 to 12 carbon atoms, for example. The alkyl group may be optionally substituted with one or more substituents.

The term "alkoxy group" may mean, for example, an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms unless otherwise specified. The alkoxy group may be linear, branched or cyclic. In addition, the alkoxy group may be optionally substituted with one or more substituents.

The term "alkylene group" or "alkylidene group" may mean, for example, an alkylene group or an alkylidene group having 1 to 12 carbon atoms, 4 to 10 carbon atoms, or 6 to 9 carbon atoms unless otherwise specified. The alkylene group or alkylidene group may be, for example, straight-chain, branched-chain or cyclic. In addition, the alkylene group or the alkylidene group may be optionally substituted with one or more substituents.

The term "alkenyl group" may mean, for example, an alkenyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms unless otherwise specified . The alkenyl group may be, for example, linear, branched or cyclic. In addition, the alkenyl group may be optionally substituted with one or more substituents.

In the general formulas (1) and (2), P may be, for example, an acryloyl group, a methacryloyl group, an acryloyloxy group or a methacryloyloxy group, an acryloyloxy group or a methacryloyloxy group, Acryloyloxy group.

Examples of the substituent which may be substituted in the specific functional group in the present invention include alkyl groups, alkoxy groups, alkenyl groups, epoxy groups, oxo groups, oxetanyl groups, thiol groups, cyano groups, carboxyl groups, acryloyl groups, methacryloyl groups, Acryloyloxy group, methacryloyloxy group, aryl group, and the like, but the present invention is not limited thereto.

The -OQP, which may be present in at least one of the formulas (1) and (2) or the moiety of the formula (2), may for example be present at the position of R ₃ , R ₈ or R ₁₃ . Further, the substituents constituting benzene substituted with -OQP and connected to each other may be, for example, R ₃ and R ₄ , or R ₁₂ and R ₁₃ . The substituent other than -OQP or the residue of the formula (2) in the compound of the formula (1) or the residue of the formula (2) or the substituent other than the substituent which is bonded to each other to form benzene is, for example, hydrogen, halogen, a straight or branched An alkoxycarbonyl group having 1 to 4 carbon atoms, a linear or branched alkoxycarbonyl group having 1 to 4 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, A straight chain or branched chain alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 4 to 12 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkoxycarbonyl group containing a straight-chain or branched alkoxy group having 1 to 4 carbon atoms, or a cyano group.

The polymerizable liquid crystal compound may be included in the liquid crystal layer in a horizontally aligned state. In one example, the polymerizable liquid crystal compound may be polymerized in a horizontally aligned state and contained in the liquid crystal layer. The term &quot; horizontal alignment &quot; means that the optical axis of the liquid crystal layer including the liquid crystal compound is aligned with the plane of the liquid crystal layer by about 0 to about 25 degrees, about 0 to about 15 degrees, about 0 to about 10 degrees, To about 5 degrees or about 0 degrees.

The liquid crystal layer may be formed so that incident light, for example, light incident through the polarizer can be divided into two or more kinds of lights having different polarization states. For this purpose, for example, the liquid crystal layer may include first and second regions having different phase delay characteristics. In the present specification, &quot; the phase delay characteristics of the first and second regions are different from each other &quot; means that the first and second regions are equal to each other when the first and second regions are all regions having phase delay characteristics Or a case in which the optical axis is formed in different directions and the phase delay values are different from each other, and a case in which the optical axis is formed in a different direction with the same phase delay value. In another example, &quot; the phase delay characteristics of the first and second regions are different &quot; means that any one of the first and second regions has a phase delay characteristic and the other region has an optical May be an isotropic region. An example of such a case is a form in which the liquid crystal layer has both a region including a liquid crystal compound and a region not including a liquid crystal compound. The phase delay characteristics of the first or second region can be controlled by, for example, adjusting the alignment state of the liquid crystal compound, the refractive index relationship of the liquid crystal layer, or the thickness of the liquid crystal layer.

The first area A and the second area B may be arranged adjacent to each other in a stripe shape extending in a common direction as shown in Fig. 1, alternatively, or alternately arranged in a lattice pattern as shown in Fig. 3 And may be alternately arranged.

When the optical element is used for displaying stereoscopic images, any one of the first and second regions may be a left eye image signal polarization control region (hereinafter referred to as &quot; LC region &quot;), One region may be a right eye image signal polarization control region (hereinafter referred to as &quot; RC region &quot;).

The two or more kinds of lights having different polarization states, which are divided by the liquid crystal layer including the first and second regions, include, for example, two types of linearly polarized lights having substantially perpendicular directions , Or left circularly polarized light and right circularly polarized light.

In this specification, when defining the angle and using terms such as vertical, horizontal, orthogonal, or parallel, each means substantially vertical, horizontal, orthogonal, or parallel, unless otherwise specified, , Manufacturing tolerance (error) or variation, and the like. Thus, for example, each of the above cases may include an error within about +/- 15 degrees, an error within about +/- 10 degrees, or an error within about +/- 5 degrees.

In one example, one of the first and second regions is a region through which the polarization axis of the incident light is not rotated but is transmitted as it is, and the other region is a region in which the polarization axis of the incident light is orthogonal to the polarization axis of the light transmitted through the other region It is possible to rotate and transmit it in a direction. In this case, the region containing the polymerizable liquid crystal compound in the liquid crystal layer may be formed in only one of the first and second regions. In the above, the region where the liquid crystal layer is not formed may be an empty space, or a resin layer or a resin film or sheet which is glass or optically isotropic may be formed. In another example, any one of the first and second regions may be an area that can convert incident light into left circularly polarized light and transmit the converted light, and the other area may be an area that can transmit incident light, Lt; / RTI &gt; In this case, the first and second regions may be regions having optical axes which have the same phase delay value and are formed in different directions from each other, or one region may be a region capable of delaying incident light by a quarter wavelength of the wavelength , And the other area may be an area capable of delaying the incident light by 3/4 wavelength of the wavelength.

In one example, the first and second regions have the same phase delay value, for example, numerical values capable of delaying the incident light by a quarter wavelength of the wavelength, and are formed in different directions And may be an area having an optical axis. The angle formed by the optical axes formed in different directions from each other may be, for example, about 90 degrees.

In the case where the first and second regions are regions having optical axes that are formed in different directions from each other, the line bisecting the angle formed by the optical axes of the first and second regions is an absorption axis of the polarizer included in the optical element And may be formed to be vertical or horizontal.

Fig. 3 is an exemplary diagram for explaining the arrangement of the optical axis in the case where the first and second regions A and B in the example of Fig. 1 or 2 are regions having optical axes formed in mutually different directions. Referring to FIG. 3, a line bisecting the angle formed by the optical axes of the first and second regions A and B may mean a line bisecting the angle of (? 1 +? 2). For example, if? 1 and? 2 are at the same angle, the bisector may be formed in a direction parallel to the boundary line L of the first and second regions A and B. In addition, the angle formed by the optical axes of the first and second regions in the above, that is, (? 1 +? 2) may be, for example, 90 degrees.

The optical element may further comprise a substrate layer. When the base layer is further included, the liquid crystal layer may be formed on one side of the base layer. The base layer may be a single layer or a multi-layer structure.

As the base layer, for example, a glass base layer or a plastic base layer can be used. Examples of the plastic substrate layer include a cellulose resin such as TAC (triacetyl cellulose) or DAC (diacetyl cellulose); COP (cyclo olefin polymer) such as norbornene derivatives; Polyolefins such as polyethylene (PE) or polypropylene (PVP), polyvinyl alcohol (PVA), polyether sulfone (PES), polyetheretherketone (PEEK) a sheet or a film including polyetherimide, polyetherimide, polyetheretherketone (PEN), polyetheretherketone (PEN), polyetheretherketone (PEN), polyetheretherketone (PEN), polysulfone (PSF)

The substrate layer, for example, the plastic substrate layer, may have a refractive index lower than that of the liquid crystal layer. The refractive index of the exemplary substrate layer ranges from about 1.33 to about 1.53. If the substrate layer has a refractive index lower than that of the liquid crystal layer, it is advantageous in, for example, improvement in luminance, prevention of reflection, and improvement in contrast characteristics.

The plastic substrate layer may be optically isotropic or anisotropic. When the substrate layer is optically anisotropic, the optical axis of the substrate layer may be arranged to be perpendicular or horizontal to a line bisecting the angle formed by the optical axes of the first and second regions.

The base layer may comprise an ultraviolet light absorber or an ultraviolet absorber. By incorporating an ultraviolet screening agent or an absorbent into the substrate layer, deterioration of the liquid crystal layer due to ultraviolet rays can be prevented. Examples of the ultraviolet light blocking agent or absorbing agent include a salicylic acid ester compound, a benzophenone compound, an oxybenzophenone compound, a benzotriazole compound, a cyanoacrylate compound or a benzoate an organic substance such as a benzoate compound or the like, or an inorganic substance such as zinc oxide or a nickel complex salt. The content of the ultraviolet screening agent or the absorbent in the base layer is not particularly limited and may be suitably selected in consideration of the objective effect. For example, in the production process of the plastic substrate layer, the ultraviolet screening agent or the absorbent may be contained in an amount of about 0.1% to 25% by weight based on the main material of the substrate layer.

The thickness of the base layer is not particularly limited and can be suitably adjusted according to the intended use.

Exemplary optical elements may further include an orientation layer between the substrate layer and the liquid crystal layer. For example, referring to FIG. 4, the optical element may sequentially include a liquid crystal layer 101, an orientation layer 102, and a base layer 103. The alignment layer may be a layer that serves to align the liquid crystal compound of the liquid crystal layer. As the alignment layer, a conventional alignment layer known in the art, for example, an alignment layer formed in an imprinting manner, a photo alignment layer, or a rubbing alignment layer can be used. The orientation layer may have an arbitrary structure, and in some cases, orientation can be imparted without orientation layer by a method of directly rubbing or stretching the base layer.

The optical element may further include a polarizing plate. The polarizing plate 201 may be attached to the liquid crystal layer 101, for example, as shown in Fig.

The polarizing plate may include a polarizer. In the present specification, the terms "polarizer" and "polarizer plate" refer to objects that are distinguished from each other. In other words, the term polarizer means a functional element, a film or a sheet per se which is capable of extracting light oscillating in one direction from the incident light while vibrating in various directions, and the term polarizer is a laminate comprising at least the polarizer . &Lt; / RTI &gt; Examples of other elements, films or sheets that can be included in the polarizing plate together with the polarizer include a polarizer protective layer and the like described later. The polarizer of the polarizing plate may include a light absorption axis formed in a predetermined direction and a light transmission axis perpendicular to the light absorption axis. As the polarizer, for example, a conventional polarizer such as a polyvinyl alcohol (PVA) polarizer can be used.

A polarizer protective layer may be formed on one side or both sides of the polarizer in the polarizer. Examples of the polarizer protective layer include a cellulose film such as TAC or DAC, an amorphous polyolefin film, a polyester film, an acrylic resin film, a polycarbonate film, a polysulfone film, an alicyclic polyimide film or a cyclic olefin polymer (COP) Etc. may be exemplified by a resin film or a resin layer cured by electromagnetic waves such as ultraviolet rays.

The polarizing plate may be attached to the liquid crystal layer by an adhesive layer or a pressure-sensitive adhesive layer. For example, in the case where the liquid crystal layer is attached to the polarizer of the polarizing plate, an adhesive layer is used, and in the case where the liquid crystal layer is attached to another layer of the polarizing plate, for example, the polarizing protective layer, a pressure sensitive adhesive layer may be used. Further, a pressure-sensitive adhesive layer may be formed on the surface of the polarizing plate, for example, the surface opposite to the surface facing the liquid crystal layer. In the case where the polarizing plate and the liquid crystal layer are attached by the pressure-sensitive adhesive layer, for convenience of explanation, the pressure-sensitive adhesive layer adhering the polarizing plate and the liquid crystal layer is referred to as a first pressure-sensitive adhesive layer and the side opposite to the surface facing the liquid- The pressure-sensitive adhesive layer formed on the surface of the first pressure-sensitive adhesive layer may be referred to as a second pressure-sensitive adhesive layer. 6 shows an element having a structure including a second pressure sensitive adhesive layer 302, a polarizing plate 201, a first pressure sensitive adhesive layer or an adhesive layer 301 and a liquid crystal layer 101 as an exemplary optical element.

The second pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer for attaching the optical element to the optical device. As the optical device, for example, a liquid crystal panel of a liquid crystal display device or a video display device of a stereoscopic image display device can be exemplified. .

The adhesive layer may have a glass transition temperature of 36 캜 or higher, 37 캜 or higher, 38 캜 or higher, 39 캜 or higher, 40 캜 or higher, 50 캜 or higher, 60 캜 or higher, 70 캜 or higher, . By attaching the liquid crystal layer and the polarizer to the adhesive layer having the glass transition temperature, an optical element having excellent durability can be provided. The adhesive layer as described above can stably maintain the phase delay characteristic of the liquid crystal layer. The upper limit of the glass transition temperature is not particularly limited, but may be, for example, about 200 캜, about 150 캜 or about 120 캜.

The adhesive layer may also have a thickness of 6 占 퐉 or less, 5 占 퐉 or less, or 4 占 퐉 or less. The adhesion to the liquid crystal layer and the durability of the phase delay characteristics of the liquid crystal layer can be properly maintained at such a thickness. The lower limit of the thickness of the adhesive layer may be, for example, 0.1 mu m, 0.3 mu m, or 0.5 mu m.

In one example, the adhesive layer may be an active energy ray curable adhesive layer. The adhesive layer may comprise an adhesive composition cured by irradiation of an actinic energy ray. The term &quot; curing of an adhesive composition or a pressure-sensitive adhesive composition &quot; may mean a process in which adhesive or tackiness is expressed by physical or chemical action or reaction of the components contained in the composition. In the above, "active energy ray curable type" may mean an adhesive or adhesive composition of the type in which the curing is induced by irradiation of an active energy ray. The term &quot; active energy ray &quot; as used herein includes alpha-particle beams, proton beams, and the like, as well as microwaves, infrared (IR), ultraviolet A particle beam such as a neutron beam or an electron beam may be included, and ultraviolet rays or an electron beam may be used.

The adhesive layer may comprise a radically polymerizable compound or a cationically polymerizable compound. In one example, the radical or cationic polymerizable compound may be included in the adhesive layer in a polymerized form. In the above, the radical polymerizable compound may mean a compound capable of being polymerized by a radical reaction, for example, a radical reaction by irradiation of an active energy ray to form an adhesive, and the cationic polymerizable compound may be a cationic reaction, May mean a compound capable of forming an adhesive by polymerization by cationic reaction by irradiation of active energy rays. Each of the compounds may be included in the adhesive composition, and the adhesive may be formed through the curing reaction of the composition.

The adhesive composition may include, for example, only one kind of a radical polymerizable compound or a cationic polymerizable compound, or both types.

Examples of the cationic polymerizable compound include an epoxy compound, a vinyl ether compound, an oxetane compound, an oxolane compound, a cyclic acetal compound, a cyclic lactone compound, a thiirane compound, a thiovinyl ether compound, spirortho ester compounds, ethylenically unsaturated compounds, cyclic ether compounds or cyclic thioether compounds, and epoxy compounds can be used, for example.

As the cationic polymerizable epoxy compound, for example, an epoxy resin, an alicyclic epoxy compound, an aliphatic epoxy compound or an aromatic epoxy compound can be exemplified. As the epoxy resin, cresol novolak type epoxy resin or phenol novolak type epoxy resin and the like can be exemplified. The epoxy resin, the weight average molecular weight _{(M w; Weight Average Molecular Weight} ) may be in the range of 1000 to 5000 or 2000 to 4000. In the present specification, the weight average molecular weight means a value converted to standard polystyrene measured by GPC (Gel Permeation Chromatograph), and unless otherwise specified, the term "molecular weight" means "weight average molecular weight". When the molecular weight is 1000 or more, the durability of the adhesive layer can be suitably maintained, and when it is 5000 or less, the workability such as coating property of the composition can be effectively maintained.

 The alicyclic epoxy compound may mean a compound containing at least one alicyclic epoxy group. The term &quot; alicyclic epoxy group &quot; means a functional group having an aliphatic saturated hydrocarbon ring, and the two carbon atoms constituting the ring also constitute an epoxy group.

As the alicyclic epoxy compound, for example, epoxycyclohexylmethyl epoxycyclohexanecarboxylate compound; Epoxycyclohexanecarboxylate compounds of alkanediol; An epoxycyclohexylmethyl ester compound of dicarboxylic acid; Epoxycyclohexyl methyl ether compounds of polyethylene glycol; Epoxycyclohexyl methyl ether compounds of alkanediol; Diepoxy trispyrene compounds; Diepoxy monospiro compounds; Vinylcyclohexene diepoxide compounds; An epoxy cyclopentyl ether compound or a diepoxy tricyclodecane compound, and specifically, 7-oxabicyclo [4,1,0] heptane-3-carboxylic acid and (7-oxa-bicyclo [ 1, 0] hept-3-yl) methanol; Ester of 4-methyl-7-oxabicyclo [4,1,0] heptane-3-carboxylic acid with (4-methyl-7-oxa-bicyclo [ freight; Esters of 7-oxabicyclo [4,1,0] heptane-3-carboxylic acid with 1,2-ethanediol; (7-oxabicyclo [4,1,0] hept-3-yl) methanol and adipic acid; (4-methyl-7-oxabicyclo [4,1,0] hept-3-yl) methanol and adipic acid; Or an ether of (7-oxabicyclo [4,1,0] hept-3-yl) methanol and 1,2-ethanediol may be used.

In one example, as the alicyclic epoxy compound, a compound having a bifunctional epoxy compound, that is, a compound having two epoxies, wherein the two epoxy groups are all alicyclic epoxy groups, can be used.

As the aliphatic epoxy compound, an epoxy compound having an aliphatic epoxy group rather than an alicyclic epoxy group can be exemplified. For example, polyglycidyl ethers of aliphatic polyhydric alcohols; Polyglycidyl ethers of alkylene oxide adducts of aliphatic polyhydric alcohols; Polyglycidyl ethers of polyester polyols of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of polyester polycarboxylic acids of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Dimers, oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate; Or an oligomer or polymer obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate and other vinyl monomers, and examples thereof include aliphatic polyhydric alcohols or polyglycidyl Ethers may be used, but are not limited thereto.

Examples of the aliphatic polyhydric alcohols include, for example, aliphatic polyhydric alcohols having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms, Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl- Pentanediol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, Pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl- Aliphatic diols such as octanediol, 1,9-nonanediol, and 1,10-decanediol; Alicyclic diols such as cyclohexane dimethanol, cyclohexanediol, hydrogenated bisphenol A and hydrogenated bisphenol F; Trimethylol ethane, trimethylol propane, hexitol, pentitol, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, tetramethylol propane and the like.

Examples of the alkylene oxides include alkylene oxides having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms and 1 to 4 carbon atoms such as ethylene oxide Seed, propylene oxide, or butylene oxide may be used.

Examples of the aliphatic polycarboxylic acid include aliphatic polycarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, , 2-methyladipic acid, 3-methyladipic acid, 3-methylpentanedioic acid, 2-methyloctanedioic acid, 3,8-dimethyldecanedioic acid, 3,7-dimethyldecanedioic acid, Dicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1 , 4-cyclohexanedicarboxylic acid, 1,4-dicarboxylmethylene cyclohexane, 1,2,3-propanetricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 1,2 , 3,4-cyclobutanetetracarboxylic acid, and the like, but are not limited thereto.

As the aliphatic epoxy compound, a compound containing no alicyclic epoxy group and containing at least three epoxy groups or three epoxy groups is suitable when considering curability, weatherability and refractive index characteristics, but is not limited thereto.

Examples of the aromatic epoxy compounds include epoxy compounds containing an aromatic group in the molecule, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S epoxy resins or brominated bisphenol type epoxy resins; Novolak type epoxy resins such as phenol novolak type epoxy resin or cresol novolak type epoxy resin; Cresol epoxy resin, resorcinol glycidyl ether, and the like.

As the cationic polymerizable compound, a silane compound having a cationic polymerizable functional group can be exemplified. Such a compound can be used as a component capable of improving the adhesive force by controlling the surface energy of the adhesive, for example. As the silane compound, for example, a compound represented by the following formula (3) can be used.

(3)

Si (R ₁ ) _n (R ₂ ) _4-n

In formula (3), R ₁ is a cationic polymerizable functional group bonded to a silicon atom, R ₂ is a hydrogen, a hydroxyl group, an alkyl group or an alkoxy group as a functional group bonded to a silicon atom, and n is a number of 1 to 4.

Examples of the cationic polymerizable functional group include a cyclic ether or vinyloxy group such as an alkenyl group such as a vinyl group, a glycidyl group or an oxetanyl group, or a vinyloxy group such as an alkenyl group, a cyclic ether group or a vinyloxy group Functional groups and the like can be exemplified.

In formula (3), n may be, for example, 1 or 2.

As the silane compound, an oligomer type silane compound in which the cationic polymerizable functional group is introduced into the molecule of a siloxane oligomer which is a low molecular weight silicone resin in which the terminal of the molecular chain is blocked with an alkoxysilyl group can also be used.

As the radically polymerizable compound, a compound having a radically polymerizable functional group such as an acryloyl group or a methacryloyl group and capable of being polymerized to form an adhesive can be used.

In one example, the radically polymerizable compound may be an acrylamide-based compound. As the acrylamide radical polymerizable compound, a compound represented by the following general formula (4) can be exemplified.

[Chemical Formula 4]

In formula (4), R ₁ and R ₂ are each independently hydrogen, an alkyl group or a hydroxyalkyl group, or R ₁ and R ₂ are connected to form a heterocyclic structure containing nitrogen, and R ₃ is hydrogen or an alkyl group.

The term &quot; heterocyclic structure &quot;, unless otherwise specified, may mean a structure of a cyclic compound containing at least two or more different atoms as ring constituting atoms. In the case of formula (4), a heterocyclic structure, e.g., R ₁ and including the nitrogen of formula I is R ₂ is connected to 3 to 20, 3 to 16, 3 to 12 or 3 Lt; / RTI &gt; to 8 ring members. In addition to the nitrogen, the atom to be included in the heterocyclic structure may be carbon, oxygen, or sulfur. As long as the heterocyclic structure is formed, in addition to the nitrogen of Formula 4 to which R ₁ and R ₂ are bonded, . The heterocyclic structure may not contain an unsaturated bond such as a carbon-carbon double bond, and may contain one or more, if necessary, optionally substituted with one or more substituents.

Examples of the compound of formula (4) include, but are not limited to, (meth) acrylamide, N-alkyl acrylamide, N-hydroxyalkyl (meth) acrylamide or N-acryloylmorpholine.

As the radical polymerizing compound, a compound including a heterocyclic acetal structure can also be exemplified. As used herein, the term &quot; heterocyclic acetal structure &quot; may mean a heterocyclic structure including a structure in which two oxygen atoms are bonded to one and the same carbon atom by a single bond. That is, the compound may be, for example, a compound containing both a functional group containing a heterocyclic acetal structure and the radically polymerizable functional group at the same time. The compound can serve, for example, as a diluent for controlling the viscosity of the composition and can also be used for improving the adhesion with the liquid crystal layer.

The heterocyclic acetal structure may comprise from 4 to 20, from 4 to 16, from 4 to 12 or from 4 to 8 ring-constituting atoms and may be optionally substituted by one or more substituents .

As the heterocyclic acetal structure, a structure represented by the following formula (5) or (6) can be exemplified. Accordingly, the radically polymerizable compound may include a monovalent residue derived from a compound represented by the following formula (5) or (6) together with a radically polymerizable functional group.

[Chemical Formula 5]

[Chemical Formula 6]

Formula (5) or in 6 R ₄ and R ₅ is a hydrogen or an alkyl group, each independently, Q, P, R and T are each independently a carbon atom or oxygen being wonjayi, Q, P, R and T 2 of which are oxygen And A and B each independently represent an alkylene group or an alkylidene group having 1 to 5 carbon atoms.

As the radically polymerizable compound having a heterocyclic acetal structure, a compound represented by the following general formula (7) can be exemplified.

(7)

In the general formula 7 R ₆ is a hydrogen or an alkyl group, R ₇ is an alkyl group with one derived from the structure of the general formula 5 or 6 are replaced by the monovalent residue or residues.

Examples of the compound represented by the general formula (7) include (2-ethyl-2-methyl-1,3-dioxolane-4- methyl-1,3-dioxolane-4-yl) methyl acylate, (2-isobutyl-2-methyl-1,3-dioxolane-4-yl ) methyl acylate or (1,4-dioxaspiro [4,5] dec-2-yl) methyl acrylate) or the like But is not limited thereto.

As the radical polymerizable compound, monomers represented by any one of the following formulas (8) to (10) can be exemplified.

[Chemical Formula 8]

[Chemical Formula 9]

[Chemical formula 10]

Wherein R is hydrogen or an alkyl group, A, B, T, U and W are each independently an alkylene group or an alkylidene group, Q is an alkyl group or an aryl group, and n is a number of 0 to 5 .

The term &quot; aryl group &quot; may mean a monovalent residue derived from a compound or derivative thereof including a structure containing benzene or two or more benzenes condensed or bonded, unless otherwise specified. The aryl group may be, for example, an aryl group having 6 to 22 carbon atoms, 6 to 16 carbon atoms, or 6 to 13 carbon atoms, and examples thereof include phenyl, phenylethyl, phenylpropyl, benzyl, tolyl, (xylyl group) or a naphthyl group.

In formula (8), n may be, for example, from 0 to 3 or from 0 to 2. Examples of the compound of the general formula (8) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylate, 2-hydroxyethyleneglycol (meth) acrylate or 2-hydroxypropyleneglycol (meth) acrylate, but are not limited thereto.

In Formula 9, T may be, for example, an alkylene group having 1 to 4 carbon atoms, and examples of the compound include beta-carboxyethyl (meth) acrylate. In the compound of formula (10), Q is, for example, an alkyl group having 1 to 4 carbon atoms, and U and W may be, for example, independently of each other an alkylene group having 1 to 4 carbon atoms. Such compounds include, but are not limited to, 2- (2-ethoxyethoxy) ethyl (meth) acrylate and the like.

As the radical polymerizable compound, a compound represented by the following general formula (11) can also be exemplified, and such a compound can be used, for example, for improving the durability of an adhesive.

(11)

In Formula (11), R is hydrogen or an alkyl group, and P is a monovalent residue derived from an aliphatic saturated hydrocarbon cyclic compound.

In formula (11), the monovalent residue may mean a monovalent residue derived from an aliphatic saturated hydrocarbon cyclic compound, specifically, a compound in which carbon atoms are bonded in a ring form, which is not an aromatic compound, or a derivative of the compound. The aliphatic saturated hydrocarbon cyclic compound may be, for example, an aliphatic saturated hydrocarbon cyclic compound having 3 to 20 carbon atoms, 6 to 15 carbon atoms, or 8 to 12 carbon atoms. Examples of such monovalent residues include isobornyl, cyclohexyl, norbornanyl, norbornenyl, dicyclopentadienyl, ethynylcyclohexane, ethenyl Cyclohexene group, or ethynyl decahydronaphthalene group, and in one example, an isoboronyl group may be used, but the present invention is not limited thereto.

As the radical polymerizable compound, an isocyanate functional acrylic acid ester compound may also be used. As the compound, any compound may be used without particular limitation, provided that it is a compound containing an isocyanate group and an acrylic group at the same time. As such a compound, for example, an isocyanate-functional aliphatic acrylic ester may be used. For example, a compound represented by the following formula (12) may be used.

[Chemical Formula 12]

In the general formula (12), R represents hydrogen or an alkyl group, and L represents a divalent hydrocarbon group.

Examples of the divalent hydrocarbon group in formula (12) include divalent aliphatic hydrocarbon groups such as divalent aliphatic hydrocarbon groups having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms An aliphatic hydrocarbon group may be used. The divalent hydrocarbon group includes, for example, straight chain, branched or cyclic alkylene or alkynylene groups; A straight chain, branched or cyclic alkenylene group; Or a linear, branched or cyclic alkynylene group. The hydrocarbon group may be, for example, a linear or branched alkylene group or an alkynylene group having 1 to 8 carbon atoms.

The compound is a (meth) and the like one oxyalkylene acryloyl isocyanate can be exemplified (meth) acryloyloxy (C _{1 -8)} yloxy (C _{1 -4)} alkyl isocyanate, (meth) acrylic Alkyl isocyanate or (meth) acryloyloxyethyl isocyanate, and the like, but are not limited thereto. In the (C _{1 -8)} alkyl, having 1, 2, 3, 4, 5, 6, 7 or 8 means a straight-chain, branched-chain or cyclic alkyl, and (C _{1 -4)} alkyl, Means straight, branched or cyclic alkyl having 1, 2, 3 or 4 carbon atoms.

As the isocyanate functional acrylic acid ester compound, for example, a compound represented by the following formula (13) can also be used.

[Chemical Formula 13]

In formula (13), R represents hydrogen or an alkyl group, and Z represents a tetravalent hydrocarbon group.

As the tetravalent hydrocarbon group, for example, a tetravalent aliphatic hydrocarbon group can be used, and specifically, a tetravalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms Can be used. For example, straight chain, branched or cyclic alkanes; Straight chain, branched or cyclic alkenes; Or tetravalent hydrocarbons derived from straight chain, branched or cyclic alkyne. The hydrocarbon group may be, for example, a tetravalent hydrocarbon group derived from a linear or branched alkane having 1 to 8 carbon atoms.

As such a compound, a compound distributed under the name of Laromer LR9000 (BASF) can be exemplified.

Examples of the lithaccharide polymerizable compound include compounds having a heterocyclic moiety such as tetrahydrofurfuryl (meth) acrylate or (meth) acryloyl morpholine Can also be used.

As the adhesive, a cationically curable adhesive composition containing an alicyclic and / or aliphatic epoxy compound as a main component and a silane compound having an oxetane compound or the cationically polymerizable functional group as a diluent or an additive, if necessary, as a cationic polymerizable compound ; A radical-curing adhesive composition comprising, as a main component, the acrylamide-based compound as the radical polymerizing compound and optionally other radical polymerizing compounds as a subcomponent; As the radical polymerizing compound, an adhesive composition comprising a compound represented by any one of the above formulas (8) to (10) as a main component and, if necessary, another radical polymerizing compound, or the epoxy resin or the alicyclic epoxy compound and the aliphatic epoxy An adhesive containing a mixture of a compound and a radically polymerizable compound represented by any one of the above formulas (8) to (10) in a cured state may be used, but the present invention is not limited thereto.

The selection of each component and the proportion of each component contained in the adhesive composition can be appropriately selected in consideration of the glass transition temperature and the like.

The adhesive composition for forming an adhesive may further include a polymerization initiator. The polymerization initiator may be appropriately selected depending on the components contained in the adhesive composition, and for example, a cation polymerization initiator and / or a radical polymerization initiator may be used.

As the radical polymerization initiator, for example, an initiator such as a benzoin compound, a hydroxy ketone compound, an amino ketone compound or a phosphine oxide compound can be used. For example, a phosphine oxide compound or the like can be used. Specific examples of the radical polymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethyl anino acetophenone , 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy- 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2- hydroxyethoxy) Ethyl anthraquinone, 2-t-butyl anthraquinone, 2-t-butyl anthraquinone, 2-ethylhexyl anthraquinone, 2- Thioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal , p-dimethylamino (2,4,6-trimethylbenzoyl) -phenyl-phosphine oxide and 2 (2-hydroxy-2-methyl-1- , 4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the like, but are not limited thereto.

As the cationic polymerization initiator, for example, an initiator which releases a component capable of initiating cationic polymerization by irradiation with an active energy ray, an onium salt or an organometallic salt-based ionizing cation initiator Or non-ionized cationic initiators such as organosilanes or latent sulfonic acid series or other non-ionized compounds, and the like.

The adhesive composition may further contain additives such as a heat curing agent, a catalyst, a UV curing agent, a low molecular weight material, a silane coupling agent, a scattering body, an ultraviolet stabilizer, a colorant, a reinforcing agent, a filler, a defoaming agent, a surfactant, An additive such as one or more kinds of additives may be further included.

In the optical element, the liquid crystal layer and the polarizing plate may be directly attached to the adhesive layer, and if necessary, a primer layer may be additionally provided between the polarizing plate and the adhesive layer or between the liquid crystal layer and the adhesive layer . In this case, the kind of the primer layer that can be used is not particularly limited, and various kinds generally used for improving the adhesiveness can be used.

At least one of the first and second pressure-sensitive adhesive layers has a storage elastic modulus at 25 ° C of at least 0.02 MPa, at least 0.03 MPa, at least 0.04 MPa, at least 0.05 MPa, at least 0.06 MPa 0.07 MPa or more, 0.08 MPa or more than 0.08 MPa or 0.09 MPa or more. Further, when the liquid crystal layer and the polarizing plate are attached by the adhesive layer, the second pressure-sensitive adhesive layer may have a storage elastic modulus within the above range. When the first and / or second adhesive has a storage modulus in the above range, the upper limit of the storage modulus is not particularly limited. For example, the storage elastic modulus may be 0.25 MPa or less, 0.2 MPa or less, 0.16 MPa or less, 0.1 MPa or less, or 0.08 MPa or less. At least the second pressure-sensitive adhesive layer in the optical element may have a storage elastic modulus in the above range, and in other examples, a storage elastic modulus in excess of 0.08 MPa.

If the first and / or second pressure-sensitive adhesive layer exhibits the storage elastic modulus, the optical element exhibits excellent durability and, for example, the phase retardation property of the liquid crystal layer stably remains for a long period of time and under harsh conditions, It is possible to exhibit the light splitting property, and side effects such as light leakage and the like can be prevented in the optical device to which the optical element is applied. In addition, the hardness characteristics of the optical element are improved, exhibiting excellent resistance to external pressure or scratches, and reworkability can be appropriately maintained.

The first and / or second pressure-sensitive adhesive layers may have a thickness of 25 mu m or less, 20 mu m or less, or 18 mu m or less. If the pressure-sensitive adhesive layer has such a thickness, the durability, hardness characteristics, reworkability, and the like can be further improved. The lower the thickness of the pressure-sensitive adhesive layer is, the more excellent the physical properties are. The lower the thickness of the pressure-sensitive adhesive layer is not particularly limited, but can be adjusted in the range of about 1 탆 or more or about 5 탆 or more.

The pressure-sensitive adhesive layer may include an acrylic pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, an epoxy pressure-sensitive adhesive or a rubber pressure-sensitive adhesive.

In the case where the pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive, the pressure-sensitive adhesive can be formed, for example, by curing a pressure-sensitive adhesive composition containing both a thermosetting component, an active energy ray-curable component, or a thermosetting component and an active energy ray-curable component.

The pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing a thermosetting component may include an acrylic polymer crosslinked by a polyfunctional crosslinking agent.

As the acrylic polymer crosslinked by the polyfunctional crosslinking agent, for example, an acrylic polymer having a molecular weight of 500,000 or more can be used. By setting the molecular weight of the polymer to 500,000 or more, a pressure-sensitive adhesive layer having excellent durability under severe conditions can be formed. The upper limit of the molecular weight is not particularly limited and can be adjusted within a range of not more than 2.5 million, for example, in consideration of durability and coating property of the composition.

In one example, the acrylic polymer may be a polymer containing a (meth) acrylic acid ester monomer and a crosslinkable monomer as polymerized units.

(Meth) acrylate having an alkyl group having 1 to 20 carbon atoms in consideration of the cohesive force, the glass transition temperature, or the tackiness of the pressure-sensitive adhesive, may be used as the (meth) Acrylate may be used. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (Meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, sec-butyl (Meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate and tetradecyl (meth) acrylate. Of these, one kind or more kinds of them may be used.

The polymer may further comprise a crosslinkable monomer as polymerized units. The polymer may include, for example, 80 to 99.9 parts by weight of a (meth) acrylic acid ester monomer and 0.1 to 20 parts by weight of a crosslinkable monomer as polymerized units. The term "crosslinkable monomer" as used herein refers to a monomer that can be copolymerized with other monomers forming an acrylic polymer and can provide a crosslinkable functional group to the polymer after copolymerization. The crosslinkable functional group can react with a multifunctional crosslinking agent described later to form a crosslinked structure.

As the crosslinkable functional group, for example, a nitrogen-containing functional group such as a hydroxyl group, a carboxyl group, an epoxy group, an isocyanate group or an amino group can be exemplified. A variety of copolymerizable monomers capable of imparting such crosslinkable functional groups at the time of production of the pressure-sensitive adhesive resin are known. Examples of the cross-linking monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylate, 2-hydroxyethyleneglycol (meth) acrylate or 2-hydroxypropyleneglycol (meth) acrylate; (Meth) acryloyloxypropionic acid, 4- (meth) acryloyloxybutyric acid, acrylic acid dimer, itaconic acid, maleic acid, and Maleic anhydride and the like, or nitrogen-containing monomers such as (meth) acrylamide, N-vinylpyrrolidone or N-vinylcaprolactam, etc., and a mixture of one kind or more of the above can be used But is not limited thereto.

The acrylic polymer may contain various other monomers as polymerized units, if necessary.

For example, the acrylic polymer may further include a compound represented by the following formula (14) as a polymerization unit.

[Chemical Formula 14]

In formula (14), R represents hydrogen or an alkyl group, A represents an alkylene group or an alkylidene group, R ₁₆ represents an alkyl group or an aryl group, and n represents a number of 1 to 6.

When the pressure-sensitive adhesive layer contains, for example, a cross-linking structure of an active energy ray component described later, the compound of the general formula (14) improves the compatibility of the cross-linking structure of the cross-linking structure with the thermosetting component and improves the physical properties of the pressure- &Lt; / RTI &gt;

N in Formula 14 may be 1 to 25, 1 to 15, or 1 to 6 in another example.

Examples of the monomer of the formula (14) include alkoxyalkylene glycol (meth) acrylate, alkoxydialkylene glycol (meth) acrylate, alkoxytrialkylene glycol (meth) acrylate, alkoxytetraalkylene glycol (Meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy trialkylene glycol (Meth) acrylic acid esters or phenoxy polyalkylene glycol (meth) acrylic acid esters.

When the compound of the general formula (14) is included, the proportion thereof may be appropriately adjusted depending on the purpose, for example, 10 to 50 parts by weight based on the weight of the other monomer.

The polymer may include, in addition to the above, a nitrogen-containing monomer such as (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide or N-butoxymethyl (meth) acrylamide; Styrene-based monomers such as styrene or methylstyrene; Glycidyl (meth) acrylate; Or carboxylic acid vinyl esters such as vinyl acetate, and the like. Such additional monomers may be adjusted in a total weight ratio ranging from 20 parts by weight or less relative to the other monomers.

The acrylic polymer is produced by applying a mixture of monomers selected and blended as described above to a polymerization system such as solution polymerization, photopolymerization, bulk polymerization, suspension polymerization or emulsion polymerization can do.

As the polyfunctional crosslinking agent for crosslinking the acrylic polymer as described above in the pressure-sensitive adhesive layer, general thermosetting crosslinking agents such as an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent and a metal chelate crosslinking agent may be exemplified. Examples of the isocyanate crosslinking agent include multifunctional isocyanate compounds such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoboron diisocyanate, tetramethylxylene diisocyanate and naphthalene diisocyanate, A compound obtained by reacting a polyfunctional isocyanate compound with a polyol compound such as trimethylolpropane, and the like. Examples of the epoxy crosslinking agent include ethylene glycol diglycidyl ether, triglycidyl ether, trimethylol propane triglycidyl ether, N, N, N ', N'-tetraglycidyl ethylenediamine and glycerin diglycidyl ether. And aziridine crosslinking agents may be exemplified by N, N'-toluene-2,4-bis (1-aziridine carboxamide), N, N'-diphenylmethane- At least one member selected from the group consisting of bis (1-aziridine carboxamide), triethylene melamine, bisisoproparyl-1- (2-methyl aziridine) and tri-1-aziridinyl phosphine oxide Examples of the metal chelate crosslinking agent include compounds in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium or vanadium is coordinated to acetylacetone or ethyl acetoacetate, But are not limited thereto .

The pressure-sensitive adhesive composition comprising a thermosetting component or the pressure-sensitive adhesive layer formed of the composition contains 0.01 to 10 parts by weight or 0.01 to 5 parts by weight of the multifunctional crosslinking agent per 100 parts by weight of the acrylic polymer Can be. By controlling the ratio of the cross-linking agent to 0.01 part by weight or more and effectively controlling the cohesive force of the pressure-sensitive adhesive and further adjusting it to 10 parts by weight or less, it is possible to prevent the occurrence of inter- . However, the above ratios can be changed depending on physical properties such as the desired elastic modulus and whether or not other crosslinked structures are contained in the pressure-sensitive adhesive layer or the like.

The pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition containing an active energy ray-curable component may include a crosslinked structure of a polymerized active energy ray-polymerizable compound. The pressure-sensitive adhesive layer may contain a functional group capable of participating in the polymerization reaction by irradiation with an active energy ray, for example, an alkenyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group or the like To prepare a pressure-sensitive adhesive composition, and then irradiating the composition with an active energy ray to crosslink and polymerize the components. Examples of the compound having a functional group capable of participating in the polymerization reaction by irradiation with an active energy ray include a functional group such as an acryloyl group, a methacryloyl group, an acryloyloxy group or a methacryloyloxy group on the side chain of the acrylic polymer ; Compounds known as so-called active energy ray-curable oligomers such as urethane acrylate, epoxy acrylate, polyester acrylate or polyether acrylate, or the following polyfunctional acrylates and the like can be exemplified.

The pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive composition comprising a thermosetting component and an active energy ray-curable component simultaneously contains a crosslinked structure including an acrylic polymer crosslinked with the polyfunctional crosslinking agent and a crosslinked structure of the polymerized active energy ray- .

Such a pressure-sensitive adhesive layer is a pressure-sensitive adhesive containing a so-called Interpenetrating Polymer Network (hereinafter &quot; IPN &quot;). The term &quot; IPN &quot; may refer to a state in which at least two or more crosslinking structures exist in the pressure-sensitive adhesive layer, and in one example, the crosslinking structures may be entanglement or linking or penetrating, It can exist in a state of doing. When the pressure-sensitive adhesive layer contains IPN, an optical element excellent in durability under severe conditions and excellent in workability and suppression of light leakage or crosstalk can be realized.

In the pressure-sensitive adhesive layer containing IPN, the cross-linking polyfunctional crosslinking agent and acrylic polymer which are realized by the acrylic polymer crosslinked by the polyfunctional crosslinking agent include, for example, those described in the item of the pressure- Component may be used.

As the active energy ray-polymerizable compound of the crosslinked structure of the polymerized active energy ray-polymerizable compound, the compound described above may also be used.

In one example, the active energy pre-polymerizable compound may be a polyfunctional acrylate. As the polyfunctional acrylate, any compound having two or more (meth) acryloyl groups can be used without limitation.

In one example, as the polyfunctional acrylate, those having a ring structure in the molecule can be used. The ring structure included in the polyfunctional acrylate may be a carbon cyclic structure or a heterocyclic structure; Or a monocyclic or polycyclic structure. Examples of the polyfunctional acrylate containing a cyclic structure include monomers having an isocyanurate structure such as tris (meth) acryloxyethyl isocyanurate and monomers having an isocyanate modified urethane (meth) acrylate (e.g., an isocyanate monomer and trimethylol Propane tri (meth) acrylate, etc.), but the present invention is not limited thereto.

The active energy ray-polymerizable compound forming the crosslinking structure in the pressure-sensitive adhesive layer containing IPN may be contained in an amount of, for example, 5 to 40 parts by weight based on 100 parts by weight of the acrylic polymer, can be changed.

The pressure-sensitive adhesive layer may contain, in addition to the above-mentioned components, various additives known in the art.

For example, in the case of a composition containing an active energy ray-curable component, it may further include a photoinitiator for promoting the polymerization reaction of the component. The pressure-sensitive adhesive layer may further include at least one additive selected from the group consisting of a silane coupling agent, a tackifier resin, an epoxy resin, a curing agent, a UV stabilizer, an antioxidant, a colorant, a reinforcing agent, a filler, a defoamer, a surfactant and a plasticizer can do.

As the pressure-sensitive adhesive layer, for example, a method of applying the pressure-sensitive adhesive composition prepared by blending the above-described components by a means such as a bar coater or a comma coater, and curing the pressure-sensitive adhesive composition may be used. The method of curing the pressure-sensitive adhesive composition is not particularly limited. For example, a method of holding the composition at an appropriate temperature so that the crosslinking reaction of the acrylic polymer and the multi-functional crosslinking agent proceeds, and a method of polymerizing the active energy ray- It can be cured through a process of irradiating an active energy ray. When the maintenance at an appropriate temperature and the irradiation of the active energy ray are simultaneously required, the above process can be carried out sequentially or simultaneously. The irradiation of the active energy ray may be performed using, for example, a high-pressure mercury lamp, a non-electrode lamp, or a xenon lamp, and the conditions such as the wavelength of the activated energy ray to be irradiated, Can be selected within a range in which the polymerization of the precursor compound can be properly carried out.

In the optical element, the first or second pressure-sensitive adhesive layer may be formed by selecting an appropriate type of pressure-sensitive adhesive of the above-described type. In one example, the second pressure sensitive adhesive layer may be a pressure sensitive adhesive layer containing at least the IPN, and the first pressure sensitive adhesive layer may be a crosslinked structure of a thermosetting component, that is, a crosslinking agent comprising an acrylic polymer crosslinked by a polyfunctional crosslinking agent Structure, or may be a pressure-sensitive adhesive layer containing the IPN.

The storage elastic modulus and the kind of the first or second pressure-sensitive adhesive layer may be more appropriately selected depending on the specific structure of the optical element.

A surface treatment layer may be formed on the optical element. For example, the optical element may further include a base layer (hereinafter referred to as a protective base layer) having a surface treatment layer formed on one surface thereof. The surface of the protective substrate layer on which the surface treatment layer is formed, that is, the surface on which the surface treatment layer is not formed, may be, for example, the above-described base layer (hereinafter referred to as the first base layer) (Hereinafter referred to as a third pressure-sensitive adhesive layer) on the base layer formed on the lower side.

A base layer selected from the same categories as the first base layer described above as the protective base layer can be used.

In the structure, the second pressure-sensitive adhesive layer may have a storage elastic modulus at 25 캜 of at least 0.02 MPa, at least 0.05 MPa, or at least 0.08 MPa, at least 0.08 MPa, at most 0.25 MPa, at least 0.09 MPa, 0.16 MPa. &Lt; / RTI &gt; The second pressure sensitive adhesive layer may be a pressure sensitive adhesive layer containing the IPN.

In the above structure, the first pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer containing a cross-linking structure of the thermosetting component or a pressure-sensitive adhesive layer containing IPN. The first pressure-sensitive adhesive layer may have a storage elastic modulus at 25 캜 of 0.02 MPa or more, 0.05 MPa or more, or 0.08 MPa or more. If the first pressure-sensitive adhesive layer is a pressure-sensitive adhesive layer containing a crosslinking structure of a thermosetting component, the storage elastic modulus at 25 ° C is adjusted in the range of 0.02 MPa to 0.08 MPa or 0.04 MPa to 0.08 MPa, Lt; 0 &gt; C and in the range of 0.09 MPa to 0.2 MPa or 0.09 MPa to 0.16 MPa.

The third pressure sensitive adhesive layer may be a pressure sensitive adhesive having a storage elastic modulus and a crosslinking component of the same category as the first or second pressure sensitive adhesive layer.

In one example, the third pressure-sensitive adhesive layer may have a storage elastic modulus at 25 캜 of at least 0.02 MPa, at least 0.05 MPa, or at least 0.08 MPa, at least 0.08 MPa, at most 0.25 MPa, at least 0.09 MPa, A pressure-sensitive adhesive layer having an MPa to 0.16 MPa and an IPN-containing pressure-sensitive adhesive layer may be used.

In another example, the surface treatment layer may be formed on the surface of the first base layer, for example, the surface of the first base layer opposite to the surface on which the liquid crystal layer or the orientation layer is formed. In this case, the protective substrate layer and the third pressure sensitive adhesive layer may not be formed on the optical element.

In this structure, the second pressure-sensitive adhesive layer may have a storage elastic modulus at 25 ° C of at least 0.02 MPa, at least 0.05 MPa, or at least 0.08 MPa, at least 0.08 MPa, at most 0.25 MPa, at least 0.09 MPa, To 0.16 MPa, and the first pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer having a storage elastic modulus at 25 DEG C of 0.02 MPa to 0.08 MPa or 0.04 MPa to 0.08 MPa. The second pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer containing the IPN, and the first pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer including the crosslinking structure of the thermosetting component.

Examples of the surface treatment layer include an anti-glare layer such as a high hardness layer, an anti-glare layer or an anti-glare layer, or a low reflection layer such as an AR (Anti reflection) layer or an LR .

The surface treatment layer may be formed on one main surface or both main surfaces of the base layer, or may be performed on the entire surface including the side surface of the base layer, if necessary.

The high hardness layer may be a layer having a pencil hardness of at least 1H or 2H or more under a load of 500 g. The pencil hardness can be measured, for example, according to the ASTM D 3363 standard using the pencil lead specified in KS G2603.

The high hardness layer may be, for example, a resin layer having a high hardness. The resin layer may include, for example, a room temperature curing type, a moisture curing type, a thermosetting type or an active energy ray curing type resin composition in a cured state, and in one example, a thermosetting or active energy ray curable resin composition, The active energy ray-curable resin composition may be contained in a cured state. The term &quot; cured state &quot; in the description of the hardened layer means a case where the components contained in each of the resin compositions are converted into a hard state through a cross-linking reaction or a polymerization reaction. The above-mentioned room temperature curing type, moisture curing type, thermosetting type or active energy ray curable type resin composition can be prepared by heating the cured state at room temperature or by heating in the presence of appropriate humidity or irradiation of active energy rays &Lt; / RTI &gt; composition.

In this field, various resin compositions are known which can satisfy the pencil hardness in the above-mentioned range in a cured state, and an average person can easily select a suitable resin composition.

In one example, the resin composition may include an acrylic compound, an epoxy compound, a urethane compound, a phenol compound, or a polyester compound as a main component. In the above, the "compound" may be a monomeric, oligomeric or polymeric compound.

In one example, an acrylic resin composition excellent in optical properties such as transparency and excellent in resistance to yellowing, and preferably an active energy ray-curable acrylic resin composition can be used as the resin composition.

The active energy ray-curable acrylic composition may, for example, comprise an active energy ray polymerizable polymer component and a reactive diluent monomer.

Examples of the polymer component include a mixture of a component known as the so-called active energy pre-polymerizable oligomer such as urethane acrylate, epoxy acrylate, ether acrylate or ester acrylate, or a monomer such as a (meth) acrylic acid ester monomer or the like Can be exemplified. Examples of the (meth) acrylic acid ester monomer include alkyl (meth) acrylate, (meth) acrylate having an aromatic group, heterocyclic (meth) acrylate or alkoxy (meth) acrylate. Various polymer components are known in the art for making active energy ray curable compositions, and such compounds can be selected as needed.

Examples of the reactive diluting monomer that can be contained in the active energy ray-curable acrylic composition include monomers having one or more active energy ray-curable functional groups such as an acryloyl group or a methacryloyl group, , For example, the above (meth) acrylic acid ester monomers and multifunctional acrylates can be used. As the polyfunctional acrylate, an appropriate type may be selected among the compounds described in the pressure-sensitive adhesive item.

The selection of the above-mentioned components for forming the active energy ray-curable acrylic composition, the blending ratio of the selected components and the like are not particularly limited and can be adjusted in consideration of the hardness and other physical properties of the desired resin layer.

As the AG (anti-glare) layer or the SG (Semi-glare) layer, for example, a resin layer including a resin layer or particles having uneven surfaces formed thereon, A resin layer which is a particle can be used. As the resin layer, for example, a resin layer used for forming the high hardness layer may be used. In the case of forming the anti-glare layer, it is not necessary to adjust the components of the resin composition so that the resin layer necessarily exhibits high hardness, but a resin layer may be formed so as to exhibit high hardness.

The method of forming the uneven surface on the resin layer is not particularly limited. For example, the resin composition may be cured in a state in which the coating layer of the resin composition is brought into contact with a metal mold having a desired concavo-convex structure, or particles having particle diameters suitable for the resin composition may be mixed, .

The anti-glare layer may also be formed using particles having different refractive indices from the resin layer.

In one example, the difference in refractive index between the particles and the resin layer may be 0.03 or less or 0.02 to 0.2, for example. If the difference in refractive index is too small, it is difficult to cause haze. On the contrary, if the refractive index difference is excessively large, scattering in the resin layer occurs a lot and haze increases, but deterioration of light transmittance or contrast characteristics may be induced. And appropriate particles can be selected.

The shape of the particles contained in the resin layer is not particularly limited and may have, for example, spherical, elliptical, polyhedral, amorphous or other shapes. The particles may have an average diameter of 50 nm to 5,000 nm. In one example, as the particles, particles having irregularities on the surface can be used. Such particles may have a mean surface roughness (Rz) of, for example, 10 nm to 50 nm or 20 nm to 40 nm, and / or a maximum height of irregularities formed on the surface of about 100 nm to 500 nm or 200 nm to 400 nm, and the width between the irregularities may be 400 nm to 1,200 nm or 600 nm to 1,000 nm. Such particles are excellent in compatibility with the resin layer and in dispersibility therein.

As the particles, various inorganic or organic particles can be exemplified. Examples of the inorganic particles include silica, amorphous titania, amorphous zirconia, indium oxide, alumina, amorphous zinc oxide, amorphous cerium oxide, barium oxide, calcium carbonate, amorphous barium titanate, barium sulfate, Examples of the organic particles include crosslinked or non-crosslinked particles of an organic material such as an acrylic resin, a styrene resin, a urethane resin, a melamine resin, a benzoguanamine resin, an epoxy resin or a silicone resin, It is not.

The concavo-convex structure or the content of the particles formed on the resin layer is not particularly limited. The shape of the concave-convex structure or the content of the particles may be controlled such that the haze of the AG layer is about 5% to 15%, 7% to 13%, or about 10% And in the case of the SG layer, the haze can be adjusted to be about 1% to 3%. The haze can be measured according to the manufacturer's manual using a hazemeter such as HR-100 or HM-150 of Sephiroth Co.,

A low reflection layer such as an AR (anti reflection) layer or an LR (low reflection) layer can be formed by coating a low refractive material. A low refractive index material capable of forming a low reflection layer is variously known and can be suitably selected and used for the optical element. The low reflection layer can be formed to have a reflectance of about 1% or less through coating of a low refractive material.

The formation of the surface treatment layer may be carried out in the manner described in Korean Patent Publication Nos. 2007-0101001, 2011-0095464, 2011-0095004, 2011-0095820, 2000-0019116, 2000-0009647, 2000 -0018983, 2003-0068335, 2002-0066505, 2002-0008267, 2001-0111362, 2004-0083916, 2004-0085484, 2008-0005722, 2008-0063107 A material known in JP-A-2008-0101801 or JP-A-2009-0049557 can also be used.

The surface treatment layer may be formed singly, or two or more of them may be formed in combination. As an example of the combination, a case where a high hardness layer is first formed on the surface of the base layer and a low reflection layer is formed again on the surface of the base layer is exemplified.

The optical element can also satisfy the condition of the following general formula (2).

[Formula 2]

Y? 200 nm

In the general formula (2), Y denotes the width or thickness of the optical element measured after attaching the optical element to the glass substrate with the second pressure-sensitive adhesive layer and holding the optical element at 150 占 폚 and 10% relative humidity for 150 hours, 300 hours, This is the amount of change in vertical length. Y may also be, for example, 170 nm or less, 150 nm or less, 130 nm or less, 110 nm or less, 90 nm or less, 70 nm or less, 50 nm or less or 40 nm or less. The lower Y value means that the optical element has better durability and dimensional stability as the numerical value is lower, so that the lower limit is not particularly limited.

The present application also relates to a stereoscopic image display device. An exemplary stereoscopic image display device may include the optical element.

In one example, the stereoscopic image display apparatus may further include an image display element capable of generating a left eye image signal (hereinafter referred to as an L signal) and a right eye image signal (hereinafter referred to as an R signal). The liquid crystal layer of the optical element may include the first and second regions described above. The optical element is arranged such that the L signal can be transmitted through any one of the first and second regions of the liquid crystal layer and the other region is arranged so that the R signal can be transmitted, May be attached to the display element.

The optical element may be arranged so that the R and L signals are emitted from the display element and are first transmitted through the polarizing plate of the optical element and then incident on each region of the liquid crystal layer.

As long as the stereoscopic image display device includes the optical element as a light splitting element, the stereoscopic image display device can be manufactured by applying various methods known in the art.

Fig. 7 exemplarily shows an apparatus in which an observer wears polarizing glasses and can observe a stereoscopic image, as an example of the above apparatus.

7, the apparatus includes, for example, a light source 401, a polarizing plate 402 and the image display element 403, and includes a second pressure-sensitive adhesive layer 302, a polarizing plate 201, Layer 101 may be attached to the display element 403 by the second pressure-sensitive adhesive layer 302.

As the light source 401, for example, a direct-type or edge-type backlight generally used in an LCD (Liquid Crystal Display) or the like can be used.

The display element 403 may be a transmissive liquid crystal display panel including a plurality of unit pixels arranged in a row, column or matrix direction. One or more of the pixels may be combined to form a right eye image signal generating region (hereinafter referred to as RG region) for generating an R signal and a left eye image signal generating region (hereinafter referred to as LG region) for generating an L signal .

The RG and LG regions may be alternately disposed adjacent to each other with a stripe pattern extending in a common direction as shown in FIG. 8, or may be alternately disposed adjacent to each other while forming a lattice pattern as shown in FIG. The first and second regions of the optical element have an LC or RC region, respectively, and the R signal transmitted in the RG region in consideration of the arrangement of the RG and LG regions is transmitted through the polarizer 201 to the RC And the L signal may be arranged to be incident on the LC region through the polarizer 201.

The image display element 403 includes a first transparent substrate, a pixel electrode, a first alignment layer, a liquid crystal layer, a second alignment layer, a common electrode, a color filter, and a second transparent layer disposed sequentially from the light source 401 side A substrate, and the like. The polarizing plate 402 may be attached to the light incident side of the panel, that is, the light source 401 side, and the optical element may be attached to the opposite side. The polarizer included in the polarizing plate 402 and the polarizer included in the polarizing plate 201 of the optical element may be arranged such that the absorption axes of the polarizing plate and the polarizing plate 201 are at a predetermined angle, for example, 90 degrees. The light can be transmitted through the display element 403 emitted from the light source 401 or blocked.

The non-polarized light from the light source 401 of the display device 8 can be emitted to the polarizing plate 402 side in the driving state. Of the light incident on the polarizing plate 402, light having a polarization axis in a direction parallel to the light transmission axis of the polarizer of the polarizing plate 402 may be incident on the display device 403 through the polarizing plate 402. The light incident on the display element 403 and transmitted through the RG region becomes the R signal, and the light transmitted through the LG region becomes the L signal and is incident on the polarizer 201 of the optical element.

The light transmitted through the LC region and the light transmitted through the RC region among the light incident on the liquid crystal layer 101 through the polarizing plate 201 are discharged in different polarizing states. The R signal and L signal having polarization states different from each other can be incident on the right eye and the left eye of the observer wearing polarized glasses, respectively, so that the observer can observe the stereoscopic image.

An exemplary optical element of the present application may be a light splitting element, for example, an element that splits incident light into two or more kinds of light having different polarization states from each other. The optical element can be used, for example, for realizing a stereoscopic image.

Figs. 1 and 2 are diagrams exemplarily showing the arrangement of the first and second regions of the liquid crystal layer. Fig.
3 is an exemplary diagram for explaining the arrangement of optical axes of the first and second regions.
4 to 6 are views showing an example of an optical element.
Fig. 7 is a diagram exemplarily showing a stereoscopic image display device. Fig.
8 and 9 are schematic diagrams showing the arrangement of the RG region and the LG region.

Hereinafter, the optical element will be described in more detail by way of Examples and Comparative Examples, but the scope of the optical element is not limited by the embodiments shown below.

One. The liquid crystal layer  Durability evaluation

The durability of the liquid crystal layer was evaluated by measuring the rate of change of the retardation value generated after the durability test on the optical element manufactured by the examples and the comparative examples. After the optical element was cut to a length of 10 cm in length and 10 cm in length, it was attached to a glass substrate with a pressure-sensitive adhesive layer, and left at 100 ° C or 250 hours in a heat-resistant condition at 80 ° C. And the amount of decrease in the retardation value after the standing was converted into a percentage and used for the durability evaluation.

The criteria for evaluating durability are as follows.

<Evaluation Criteria>

O: When the change amounts of the phase difference values after 100 hours and 250 hours of standing in a heat-resistant condition were all less than 8%

X: When the amount of change in the phase difference value after 100 hours and 250 hours in the heat-resistant condition is 8% or more in either case

2. Crosstalk  evaluation

The crosstalk ratio at the time of observing the stereoscopic image can be defined as a ratio of the luminance in the dark state to the luminance in the bright state. In the examples and the comparative examples, it is assumed that the optical element is applied to a stereoscopic image display apparatus using polarizing glasses, and the crosstalk rate is measured in the following manner. A stereoscopic image display apparatus as shown in Fig. 7 is constructed by using an optical element. Thereafter, the stereoscopic image observation polarizing glasses are placed at the normal observation point of the stereoscopic image display apparatus. In this case, when the observer views the stereoscopic image, the normal observation point is a position distant from the center of the stereoscopic image display device by a distance corresponding to 3/2 times the horizontal length of the stereoscopic image display device, The polarizing glasses are positioned assuming that the observer observes the center of the display device. The horizontal length of the stereoscopic image display device may be a length in a horizontal direction with respect to the observer, for example, a horizontal length of the image display device, assuming that the observer observes a stereoscopic image . In the above arrangement, a luminance meter (equipment name: SR-UL2 Spectrometer) is arranged on the back surfaces of the left eye and right eye lenses of the polarizing glasses in a state in which the stereoscopic image display device outputs an L signal, . In the above, the luminance measured on the back surface of the left eye lens is the bright state, and the luminance measured on the back surface of the right eye lens is the dark state luminance. The ratio of the luminance of the dark state to the luminance of the bright state ([the luminance of the dark state] / [the luminance of the bright state]) with respect to the luminance of the bright state can be determined as a percentage and defined as the crosstalk rate have. Also, the crosstalk rate can be measured in the same manner as described above, and the luminance can be measured in the bright state and the dark state in a state in which the stereoscopic image display device is outputting the R signal. In this case, the luminance measured on the back surface of the lens for the left eye is the luminance in the dark state, and the luminance measured on the back surface of the right eye lens is the luminance in the bright state. Similarly, the ratio is determined as a percentage and can be defined as the crosstalk rate have.

3. Phase difference  And Evaluation of Refractive Index

The evaluation of the retardation and the refractive index of the optical element or the liquid crystal layer was performed using an Axoscan Axomatrix according to the manufacturer's manual for a wavelength of 550 nm.

4. Evaluation of thickness and width or length of optical element

The measurement of the transverse or longitudinal length of the optical element was performed using a Premium 600C and IView Pro program of Intec Eye MS, a three-dimensional measuring instrument. The thickness of the liquid crystal layer was measured using a spectral reflectometer, which is a device capable of evaluating the characteristics of a thin film by using an interference phenomenon between light reflected from a thin film surface and light reflected at a lower interface or a phase difference of light.

Manufacturing example  One. In the liquid crystal layer (A)  Produce

The composition for forming a photo alignment layer was coated on one surface of a TAC substrate (refractive index: 1.49, thickness: 80,000 nm) to a thickness of about 1,000 Å after drying, and dried in an oven at 80 ° C for 2 minutes. For the photo alignment layer forming composition, to the poly-norbornene (molecular weight (M _w) = 150,000) and a photoinitiator a mixture of acrylic monomer (Igacure 907) and mixed, and again the mixture toluene solvent having a cinnamate of formula 15 (Polynorbornene: acrylic monomer: photoinitiator = 2: 1: 0.25 (weight ratio)) was used in place of the composition prepared by dissolving polynorbornene in such an amount that the solid content of polynorbornene was 2 wt%.

[Chemical Formula 15]

Next, the dried composition for forming a photo-alignment layer was subjected to orientation treatment according to the method disclosed in Korean Patent Application No. 2010-0009723 to form a photo-alignment layer including first and second orientation regions oriented in different directions Respectively. A stripe-shaped light transmitting portion having a width of about 450 占 퐉 and a pattern mask in which light blocking portions are alternately formed on the upper and lower sides and left and right are placed on the dried composition, A polarizing plate having two regions formed therein was placed. Subsequently, while the TAC substrate 30 on which the photo alignment layer was formed was moved at a speed of about 3 m / min, ultraviolet rays (300 mW / cm ²⁾ were applied to the composition for photo-alignment layer via the polarizing plate and the pattern mask ) Was irradiated for about 30 seconds to perform alignment treatment. Subsequently, a liquid crystal layer was formed on the alignment layer subjected to alignment treatment. Specifically, a liquid crystal composition comprising 70 parts by weight of a multifunctional polymerizable liquid crystal compound represented by the following formula (A) and 30 parts by weight of a monofunctional polymerizable liquid crystal compound represented by the following formula (B) as a liquid crystal composition and containing a proper amount of a photo initiator (300 mW / cm &lt; ² &gt;) was irradiated for about 10 seconds to crosslink and polymerize the liquid crystal to form an alignment of the lower light alignment layer A liquid crystal layer in which first and second regions having optical axes perpendicular to each other are formed is formed. The difference between the refraction index in the slow axis direction and the refraction index in the fast axis direction in the liquid crystal layer was about 0.125.

(A)

[Chemical Formula B]

Manufacturing example  2 to 9. Liquid crystal layer (B) to The liquid crystal layer (I)  Produce

The liquid crystal layer was formed in the same manner as in Production Example 1 except that the composition of the liquid crystal mixture was adjusted so that the difference in refractive index between the slow axis direction and the fast axis direction was 0.03 to obtain a thickness of about 0.3 탆 and 1 탆 And a liquid crystal layer having a thickness of 2.5 m were respectively formed (Production Examples 2 to 4). A liquid crystal layer was produced in the same manner as in Production Example 1, except that a liquid crystal layer having a thickness of about 0.3 占 퐉 and 2.5 占 퐉 was formed (Production Examples 5 and 6). Further, after forming a liquid crystal layer in the same manner as in Production Example 1, the composition of the liquid crystal mixture was adjusted so that the difference in refractive index between the slow axis direction and the fast axis direction was 0.22 to obtain a thickness of about 0.3 탆 and 1 탆 And a liquid crystal layer having a thickness of 2.5 m were respectively formed (Production Examples 7 to 9). Table 1 below shows the difference in thickness and refractive index of each liquid crystal layer in the above production examples.

Difference in refractive index Thickness (㎛) Production Example 2 The liquid crystal layer (B) 0.03 0.3 Production Example 3 The liquid crystal layer (C) 0.03 One Production Example 4 The liquid crystal layer (D) 0.03 2.5 Production Example 5 The liquid crystal layer (E) 0.125 0.3 Production Example 6 The liquid crystal layer (F) 0.125 2.5 Production Example 7 The liquid crystal layer (G) 0.22 0.3 Production Example 8 The liquid crystal layer (H) 0.22 One Production Example 9 The liquid crystal layer (I) 0.22 2.5 Difference in Refractive Indexes: Difference between refractive index in the in-plane slow axis direction and refractive index in the fast axis direction of the liquid crystal layer

Manufacturing example  10. In the liquid crystal layer J  Produce

55 parts by weight of the multifunctional polymerizable liquid crystal compound (Formula A) and 45 parts by weight of the monofunctional polymerizable liquid crystal compound (Formula B) were compounded in the same manner as in Production Example 1 to prepare a liquid crystal composition. 1, a liquid crystal layer was prepared. The difference between the refraction index in the slow axis direction and the refraction index in the fast axis direction in the liquid crystal layer was about 0.125, and the thickness of the liquid crystal layer was 1 mu m.

Example  One.

The optical element was prepared in the following manner. (TAC film) formed on both sides of the polarizer and a polyvinyl alcohol polarizer on one side of the liquid crystal layer in the structure in which the structure prepared in Production Example 1, i.e., the TAC substrate, the orientation layer and the liquid crystal layer are sequentially formed, Using a polarizing plate and a known pressure-sensitive adhesive. Specifically, the pressure-sensitive adhesive composition was coated on the liquid crystal layer so that the thickness after curing became 1 占 퐉, the polarizing plate was laminated on the liquid crystal layer, and the composition was cured under appropriate conditions to attach the polarizing plate and the liquid crystal layer. Thereafter, a conventional acrylic pressure-sensitive adhesive layer was formed on one side of the polarizer protective film of the polarizing plate to form a TAC substrate, an alignment layer, a liquid crystal layer, a pressure-sensitive adhesive layer, a TAC film (polarizer protective film), a polyvinyl alcohol polarizer, a TAC film Film) and a pressure-sensitive adhesive layer in this order.

Example  2.

An optical element was produced in the same manner as in Example 1, except that the liquid crystal layer produced in Production Example 10 was used.

Comparative Example  1 to 8,

Optical elements were prepared in the same manner as in Example 1, except that the liquid crystal layers prepared in Production Examples 2 to 9 were used.

The durability and the crosstalk ratio of the liquid crystal layer were evaluated for the optical devices manufactured in the above-described Examples and Comparative Examples, and they are shown in Table 2 below.

Liquid crystal layer Crosstalk rate
(%) Liquid crystal layer
durability Difference in refractive index Thickness (㎛) Example 1 The liquid crystal layer (A) 0.125 One 0.5 ○ Example 2 The liquid crystal layer (J) 0.125 One 0.5 ○ Comparative Example 1 The liquid crystal layer (B) 0.03 0.3 79.5 ○ Comparative Example 2 The liquid crystal layer (C) 0.03 One 45.3 ○ Comparative Example 3 The liquid crystal layer (D) 0.03 2.5 10.3 ○ Comparative Example 4 The liquid crystal layer (E) 0.125 0.3 36 ○ Comparative Example 5 The liquid crystal layer (F) 0.125 2.5 177.4 ○ Comparative Example 6 The liquid crystal layer (G) 0.22 0.3 14.6 ○ Comparative Example 7 The liquid crystal layer (H) 0.22 One 30.7 ○ Comparative Example 8 The liquid crystal layer (I) 0.22 2.5 121.6 ○

A, B: first and second regions of the liquid crystal layer
L: a boundary between the first area and the second area
? 1,? 2: an angle formed by the optical axis of the first or second region with the boundary line L
101: liquid crystal layer
102: orientation layer
103: substrate layer
201, 402: polarizer
302: second pressure-sensitive adhesive layer
301: first pressure-sensitive adhesive layer
401: Light source
403: image display element
LG: Left eye image signal generating area
RG: right eye image signal generating area

Claims (15)

A liquid crystal layer containing a polymerizable liquid crystal compound in a polymerized form and having a difference between a refractive index in the in-plane slow axis direction and a refractive index in the fast axis direction of 0.05 to 0.2 and a thickness of 0.5 to 2.0 탆,
Wherein the polymerizable liquid crystal compound comprises a monofunctional polymerizable liquid crystal compound and a monofunctional polymerizable liquid crystal compound in a proportion of more than 0 part by weight and not more than 100 parts by weight based on 100 parts by weight of the polyfunctional polymerizable liquid crystal compound,
Wherein the liquid crystal layer has a first region and a second region which have different phase delay characteristics from each other. The optical element according to claim 1, wherein the liquid crystal layer satisfies the following general formula (1)
[Formula 1]
X < 8%
X is a percentage of the absolute value of the amount of change in the retardation value of the liquid crystal layer after the liquid crystal layer is left at 80 캜 for 100 hours with respect to the initial retardation value of the liquid crystal layer. delete delete The optical element according to claim 1, wherein the polymerizable liquid crystal compound is represented by the following formula (1):
[Chemical Formula 1]

Wherein A is a single bond, -COO- or -OCO-, and R ₁ to R ₁₀ are each independently selected from the group consisting of hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group, -OQP or to a substituent of the formula 2, R ₁ to R ₅ pair of two adjacent substituents of R ₆ to R ₁₀ or a pair of two substituents adjoining are connected to each other but form a benzene substituted with -OQP, R ₁ to at least one of R ₁₀ may be a substituent of the formula -OQP or 2, R ₁ to R ₅ 2 substituents adjacent to one or R ₆ to R _10, at least one pair of two substituents adjacent to each other is of - OQP, wherein Q is an alkylene group or an alkylidene group, P is an alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group or a meta A polymerizable functional group such as a &lt; RTI ID = 0.0 &gt; The.
(2)

Wherein B is a single bond, -COO- or -OCO-, and R ₁₁ to R ₁₅ are each independently selected from the group consisting of hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group or -OQP , Two adjacent substituents R ₁₁ to R ₁₅ are connected to each other to form benzene substituted with -OQP, at least one of R ₁₁ to R ₁₅ is -OQP, or adjacent two of R ₁₁ to R ₁₅ P is a group selected from the group consisting of an alkylene group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, An acryloyloxy group or a methacryloyloxy group, and the like. The optical element according to claim 1, wherein the polymerizable liquid crystal compound is included in the liquid crystal layer in a horizontally oriented state. delete The optical element according to claim 1, further comprising a base layer, wherein a liquid crystal layer is formed on one side of the base layer. The optical element according to claim 8, further comprising an orientation layer between the base layer and the liquid crystal layer. The optical element according to claim 1, further comprising a polarizer attached to the liquid crystal layer, the polarizer including a polarizer. The liquid crystal display device according to claim 10, wherein the first and second regions included in the liquid crystal layer each have an optical axis formed in a direction different from each other, and a line bisecting an angle formed by the optical axis of the first region and the optical axis of the second region An optical element that is perpendicular or horizontal to the optical absorption axis of the polarizer. The optical element according to claim 10, wherein the polarizing plate is attached to the liquid crystal layer by an adhesive layer or a pressure-sensitive adhesive layer. A stereoscopic image display device comprising the optical element of claim 1. 14. The stereoscopic image display apparatus according to claim 13, further comprising an image display element capable of generating a left eye image signal and a right eye image signal. 14. The liquid crystal display device according to claim 13, wherein the liquid crystal layer of the optical element has first and second regions having different phase delay characteristics from each other, and wherein the optical element is configured so that any one of the first and second regions is a left- And the other region is arranged so that a right eye image signal can be transmitted.

Images